[Closed] filament load and unload  

  RSS
mbioucas
(@mbioucas)
New Member

Hi,

 

Is there a reason for heating the bed when preheating to load and unload the filament?

If not is just a wast of energy and it could be improved in firmware.

 

Regards

Miguel

Posted : 14/07/2020 9:03 pm
karl-herbert
(@karl-herbert)
Famed Member
Posted by: @mbioucas

Hi,

 

Is there a reason for heating the bed when preheating to load and unload the filament?

If not is just a wast of energy and it could be improved in firmware.

 

Regards

Miguel

You can make changes in the PrusaSlicer according to your needs, e.g. in the start code or end code.

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 14/07/2020 9:22 pm
JoanTabb
(@joantabb)
Moderator

Hi Miguel, 

I don't generally find it a waste, but I may have different operating parameters to you. 

At the end of a print, if I want the filament removed I either select unload filament before the filament has had time to cool, or add G code to my customgcode, 'End Gcode'  to expel the filament

 

Here is a clip of my 'End Gcode' from My Palette / Canvas slicer setup.

because that always leaves a cut end at the end of a print, I always expel the filament stub automatically, so that it is ready to be removed, when I  am ready to remove it, without re heating the extruder... 

G1 E-100 F1000: Eject Filament Stub
M106 S0 ; turn off cooling fan
M104 S0 ; turn off extruder
M140 S0 ; turn off bed
G1 X0 Y200 ;  extend build plate to aid part removal

similarly , the Palette Smart load sequence creates a section of spliced multifilament  material before a print can be started, so it asks me to heat the extruder and heatbed, when they are needed for the beginning of the print. at which time I need both extruder and heatbed to be heated, so again there is no waste.

I am in the middle os a 12 hour print at the moment, so I can't test this... 

If instead of pre heating and then loading filament, you were to simply choose 'Load Filament'   the printer will ask you which material it is. !  does the printer also heat the heatbed? I have never checked. 

When using the printer for single material prints, I only change the filament if the wrong filament is installed, at the beginning of a print. so my manual process is, 
Load the SD Card with Gcode into the printer, turn the printer on, select preheat for the correct material... say PETG, whilst the printer is heating, I get my next filament ready, trimming the end if required, 
when the extruder gets to temperature, I eject the old filament and load the new filament, if the filament is different I then set preheat for the new filament, and once the filament is loaded. and confirmed, I select Print from SD Card. and this usually happens before the heatbed has achieved temperature, so I have not wasted any time. 

When a print finishes, I generally leave the filament in situ. unless it it TPU, when I will probably remove it and bag it with silica gel. 

I don't use PVA for BVOH, 

PETG and PLA don't seem to suffer a lot from moisture absorbtion in my house...    (Leaving it in a garage or similar may be more of a problem... 

If you wish to raise your idea with Prusa Developers, please go to the Prusa mk3S Github page and raise a case there. 

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 14/07/2020 9:31 pm
karl-herbert
(@karl-herbert)
Famed Member
Posted by: @mbioucas

Hi,

 

Is there a reason for heating the bed when preheating to load and unload the filament?

If not is just a wast of energy and it could be improved in firmware.

 

Regards

Miguel

I think I understand what you mean now. The preheating via the lcd menu is material based. It always heats up the nozzle and the bed. To heat only the nozzle you can do this via the settings - temperature - nozzle.

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 14/07/2020 10:14 pm
mbioucas
(@mbioucas)
New Member
Posted by: @karl-herbert
Posted by: @mbioucas

Hi,

 

Is there a reason for heating the bed when preheating to load and unload the filament?

If not is just a wast of energy and it could be improved in firmware.

 

Regards

Miguel

I think I understand what you mean now. The preheating via the lcd menu is material based. It always heats up the nozzle and the bed. To heat only the nozzle you can do this via the settings - temperature - nozzle.

Hi, 

Thanks all for the replys, this is what I mean, although for loading can make sense if you would start printing right after loading, and the GCode for unload can also help, but I think it would be nice to be able to select if the bed should heat up or not separately for each function, load and unload.

If you use the fuctions from the panel, I still think that heating up the bed when unloading makes no sense, it could heart up only when loading so you would gain some time to start printing.

Regards

Miguel

Posted : 15/07/2020 11:04 am
Makak007
(@makak007)
Trusted Member

Hi Miguel.

I think karl-herbert got the idea and philosophy behind the functions in load/unload filament command and setting/temperature/nozzle comnand.

Load/unload filament command assumes you are about to print so it heats the print bed as well. By the time you swap the filament and load the gcode, you have your print bed sort of pre-heated at least to some 80C from room temperature, thus saving some time before your print starts.

If you just decide to remove the last used filament from your printer for whatever reason, then settings/temperature/nozzle command is there and you won't waste any energy on print bed heating.

I think your proposal would make the firmware and menu unnecessarily complicated as there are both commands present already. For this reason it is likely Prusa will turn down your proposal (my humble guess).

Posted : 30/07/2020 3:15 pm
Share:

Please Login or Register